Diarrhoea - what is it?

Rhythmic contractions propel food particles along the intestinal tract, allowing nutrient absorption. The digestive system produces 10 litres of fluid (acid, enzymes, bile and lubricants) to aid this process daily. The gut reabsorbs fluid from the food passing through it, making semi-solid stools. Eight litres are reabsorbed by the small intestine and 1.9 litres by the large intestine (colon).

About 0.1 litres of fluid is excreted in the stools. For an adult, if the daily stool contains more than 0.2 litres of fluid, it is called diarrhoea.

Some doctors consider stool frequency of more than three times a day to be abnormal. However, any change in the frequency and consistency of an individual’s stool may be cause for concern.

Almost everyone gets diarrhoea occasionally; adults average four bouts a year. Diarrhoea can be acute (sudden onset) or chronic (persistent). Acute diarrhoea lasts for a several days; it is usually not serious and clears up without treatment.

However, severe or persistent diarrhoea, especially in babies, requires medical attention. Chronic diarrhoea lasts for more than four weeks. This has a significant impact on quality of life and overall health, and can be disabling and even life-threatening. Children aged three or younger are particularly vulnerable to dehydration, and babies under two months are at highest risk. Elderly patients are also prone to dehydration.

Poor sanitation and hygiene adds to the incidence of diarrhoea, and it is more common in developing countries and areas.